Ideas that go viral are the sort that spread easily. Some of the best ideas in the world never gain traction because even the most enthusiastic supporters can't explain them. Most people don't embrace things they don't understand. Even if folks do 'get it', price, complexity, and the ever present catch-22 of 'if it's popular, I'll buy it, but not before' issue can all be stumbling blocks in the success of a product.
When Magic was released in 1994, the barriers were low. The game was complex, but not too complex. The cards were cheap. Players were EVERYWHERE. It was a lot of fun! In hindsight, it's not too surprising that the game took off.
Fast-forward 10 years. Now the game is (or at least seems) very complex. Ten years of new rules, rules revisions, additional cards and abilities have created what appears to be a hard game to learn. Barrier. The cards are no longer cheap. While the cost has only gone up a bit, per card, you now must buy hundreds-to-thousands to compete with any existing player. Barrier. Players are harder to find, outside of tournaments. Barrier. Tournaments are hyper competitive affairs, focusing on prizes and victory more than fun. Barrier (to many). It's easy to see why it's harder to find new Magic players now than it used to be.
In the eyes of the general public, I think these same concerns bleed over to all trading card games (fairly or not) and publishers should take pains to address them, at least internally, when releasing a new collectible type game.
What barriers does your game have? What might crop up if it succeeds?